This invention relates generally to photodetector systems, and more particularly, to a photodetector system wherein the electrical output signal is responsive to the position of a light source with respect to the photodetector.
There is available in the prior art a large variety of systems for producing electrical signals having information content responsive to the orientation of a light source, such as the sun, relative to a photodetector. Most of the known arrangements for performing this function are complex and expensive, and also are rather bulky with their asssociated electronic signal analysis systems. One known arrangement utilizes a pair of solar cells arranged orthogonal to one another. The incident electromagnetic radiation, or sunlight, causes the solar detectors to generate respective output electrical signals having amplitudes responsive to the angle of incidence of the light. Ratio detecting circuitry is used to determine the angle of incidence with respect to the orientation of the solar detectors, by monitoring and comparing the output signals of the respective solar detectors.
A further known system for determining the direction of incident radiation utilizes a sensor head having a hemispherical convex surface area on which are terminated a plurality of optical fibers. The optical fibers are bundled and terminated at their distal ends with detectors, which are arrayed illustratively in the form of matrix. This known system, however, in addition to requiring a multiplicity of detectors arranged in a matrix, also requires complex mathematical and evaluation circuitry which render this known system unsuitable in applications where simplicity and economy are required.
Particularly in mobile systems which continually are changing their orientation with respect to the sn, it is desirable to modify the output of associated heating and cooling systems so as to take into consideration the effects of sunlight. In such systems, however, there is not often available space for a complex, multi-component sensor and associated computation circuitry. There is therefore a need for a sensor which is responsive to the position of a light source, and which also is compact and reliable.
It is, therefore, an object of this invention to provide a system for monitoring the position of a light source, the system being simple and inexpensive.
It is another object of this invention to provide a system for monitoring the position of a light source wherein only one detector is required to achieve the monitoring function.
It is also an object of this invention to provide a system for monitoring the position of a light source wherein the need for multi-detector comparator circuitry is avoided.
It is a further object of this invention to provide a system for monitoring the position of a light source wherein an output electrical signal is responsive to an angle of elevation of the light source with respect to a predetermined horizon.
It is additionally an object of this inventon to provide a system for monitoring the position of a light source wherein an output electrical signal is responsive to a predetermined azimuth angle.
It is yet a further object of this invention to provide a system for monitoring the position of a light source wherein there is not a need for fiber optic elements for directing the light to be monitored to a detector.
It is also another object of this invention to provide a system for monitoring the position of a light source wherein a high degree of compactness is achieved.
It is yet an additional object of this invention to provide a system for monitoring the position of a light source, the system being particularly suited for mobile applications.
It is still another object of this invention to provide an arrangement for controlling a mobile cooling system in response to incident sunlight being within a predetermined range of angles of elevation.
It is yet a further object of this invention to provide an arrangement for controlling a mobile cooling system in response to incident sunlight being within a predetermined range of angles of azimuth.
It is also a further object of this invention to provide an arrangement for controlling a mobile cooling system in response to the angle of incidence of sunlight.